Intensification of phosphate removal using electrocoagulation treatment by continuous pH adjustment and optimal electrode connection mode

Abstract

This paper discusses two possible ways of intensifying the electrocoagulation treatment of water containing phosphate. The first one consists of controlling the chemical composition of the water by continuous adjustment of the pH. The second aspect focuses on electrode connection modes, and the four different modes were tested monopolar in series, in parallels and independents, and finally bipolar. Experiments were conducted in a small batch reactor containing water with 100 mg P/L using electrodes of aluminum. Several electrical connections were used for the water treatment under favorable operating conditions determined by a study and presented in a previous paper. The influence of pH adjustment was conducted using different adjustment step times (no adjustment, every 30, 10 and 5 min). The kinetics of the treatment was found to be accelerated by continuous adjustment of the pH. The choice of the electrode connection modes was found to strongly affect the efficiency of the treatment, the Faradic yield, and the consumption of energy. The monopolar in parallels connection mode was found to be the most economic, whereas bipolar in parallels was found to favor a higher kinetic rate of treatment.

Keywords:

• Aluminum
• Electrode connection modes
• pH adjustment
• Electrocoagulation
• Phosphate
• Intensification